1. Field of the Invention:
The present invention relates to a recording apparatus including an electrophotographic copying machine having a unit which is capable of being detachably mounted to the apparatus, particularly to the structure of the unit or to the frames, and supporting components of the unit. On the unit, an electrostatic charge holding member such as photosensitive drum and at least one processing unit, for example, electric charging means for image formation are arranged.
The term "processing unit(s)" is to use herein for charging means mentioned above, developing means, image transfer means such as image transfer electrode and image transfer roller, separating means such as separation electrode, separation claw and buffer, and electrically neutralizing means such as neutralizing electrode and neutralizing lamp.
Generally in an electrostatic recording apparatus such as electrophotographic copying machine, it is necessary to arrange a plurality of processing units around the peripheral surface of the photosensitive drum to process an image, as is well known, and it is necessary to determine the exact position between said processing units and the surface of the photosensitive drum. Especially in case of using a medium or high speed copying machine, wherein a photosensitive drum having a narrow latitude is used, it is necessary to accurately set the correlative positive between the processing units and the photosensitive drum.
To date, in conventional electrophotographic copying machines, fixtures are provided on the frame of said machines to which a photosensitive drum is mounted, and the processing units are fixed upon said fixtures, or, as shown in FIG. 1, rails 2-7 span the machine frames A for supporting the various processing units, for example, electric charging means 8 comprising wire electrode, developing means 9, image transfer means 10, separation electrode 11, neutralizing electrode 12 and cleaning means 13, are insertedly fixed in said rails. Therefore in such a structure it is difficult to keep the relative position of said processing units to the position of the photosensitive drum 1 and adjustment of said relative positioning is made by way of inserting spacers or the like between the processing units and the fixtures or rails 2-7. Such adjustment processes account for a major proportion of the assembly process, so that the labor costs, etc for the adjustment process make the manufacturing costs comparatively high. In addition, the adjustments by inserting spacers or the like adversely affects the reproductive function of the processing units when reassembling them for maintenance, and is a bottle-neck in the maintenance procedure.